I’m currently working on a Twitter app for Windows Phone, in which – via a custom DependencyProperty – the Xaml property of each RichTextBox is bound to the text of a tweet (which includes programmatically generated Run elements with all the text). This works good enough until there are curly braces { and } in the text. I tried replacing them with { and escaping with {} but to no avail.
The weird thing is, if the curly braces show up in the middle of the text (more specifically, in the Text property of a Run element) everything’s fine, it’s only when an opening curly brace is at the beginning* or a closing curly brace is at the end* that the RichTextBox crashes. I was able to work around this by inserting zero-width spaces with ​ at the beginning and end of each Run.
However, this issue gets more complicated if there is both an opening curly brace at the beginning* and a closing curly brace at the end*. In that case, the zero-width spaces don’t seem to work anymore, so the only workaround would be to insert additional “real” characters at either the beginning or end of the text, which I obviously can’t do.
This does seem to be a bug with RichTextBox, as acknowledged in this answer over two years ago. Apparently, it hasn’t been fixed yet. So, does anyone know of any further workarounds I could try?
* can also be preceeded only by whitespace or followed only by whitespace
Okay after some more tinkering I found an easy fix. Just put a “zero-width non-joiner” character
‌(‌doesn’t work in XAML) at the beginning and end of eachRun.Apparently this character is treated differently than the zero-width space I used previously and even works if your text has curly braces at both the beginning and the end. There are of course even more invisible characters that have the same effect (check this list on Wikipedia) but the zero-width non-joiner should have the least side-effects I think.